BUILDING(8) NetBSD System Manager's Manual BUILDING(8)
NAME
BUILDING - Procedure for building NetBSD from source code.
STATUS
This document is a work-in-progress. As such, the information described
here may not match the reality of the build system as of this writing.
Once this document is completely in sync with reality, this paragraph
will be removed.
Discrepancies between this documentation and the current reality of im-
plementation are noted specially, as with the note below:
Note: This document applies only to platforms which use the new toolchain
as indicated by the default setting of USE_NEW_TOOLCHAIN in .
Platforms which have not yet been switched to the new toolchain should
continue building traditionally, using the notes specified in the file
UPDATING.
REQUIREMENTS
NetBSD is designed to be buildable on most POSIX-compliant host systems.
The basic build procedure is the same whether compiling natively (on the
same NetBSD architecture) or cross compiling (on another architecture or
OS).
This source tree contains a special subtree, ``tools'', which uses the
host system to create a build toolchain for the target architecture. The
host system must have at least C and C++ compilers in order to create the
toolchain (make is not required); all other tools are created as part of
the NetBSD build process.
Note: A couple host toolchain components are not yet available in
the tools directory. Also, some tools use non-POSIX, non-ANSI C
extensions and need to be standardized. As a result, cross-compil-
ing from systems other than NetBSD is not currently supported.
FILES
Source tree layout
BUILDING.mdoc This document (in -mdoc troff format; the original copy).
BUILDING This document (in plaintext).
Makefile The main Makefile for NetBSD; should only be run for na-
tive builds with an appropriately up-to-date version of
NetBSD make(1). (For building from out-of-date systems or
on a non-native host, see the build.sh shell script.)
UPDATING Special notes for updating from an earlier revision of
NetBSD. It is important to read this file before every
build of an updated source tree.
build.sh Bourne-compatible shell script used for building the host
build tools and the NetBSD system from scratch. Can be
used for both native and cross builds, and should be used
instead of make(1) for any source tree that is updated and
recompiled regularly.
crypto/dist/, dist/, gnu/dist/
Sources imported verbatim from third parties, without man-
gling the existing build structure. Other source trees in
bin through usr.sbin use the NetBSD make(1) ``reachover''
Makefile semantics when building these programs for a na-
tive host.
distrib/, etc/
Sources for items used when making a full release snap-
shot, such as files installed in /etc on the destination
system, boot media, and release notes.
regress/ Regression test harness. Can be cross-compiled, but only
run natively.
sys/ NetBSD kernel sources.
tools/ ``Reachover'' build structure for the host build tools.
This has a special method of determining out-of-date sta-
tus.
bin/ ... usr.sbin/
Sources to the NetBSD userland (non-kernel) programs. If
any of these directories are missing, they will be skipped
during the build.
Build tree layout
The NetBSD build tree is described in hier(7), and the release layout is
described in release(7).
CONFIGURATION
Environment variables
Several environment variables control the behaviour of NetBSD builds.
MACHINE Machine type.
MACHINE_ARCH Machine architecture.
MAKE Path name to invoke make(1) as.
MAKEFLAGS Flags to invoke make(1) with.
MAKEOBJDIR Directory to use as the .OBJDIR for the current direc-
tory. Used only if MAKEOBJDIRPREFIX is not defined.
MAKEOBJDIR can only be provided in the environment.
MAKEOBJDIRPREFIX Top level directory of the object directory tree. If
this is defined, ${MAKEOBJDIRPREFIX}/${.CURDIR} is used
as the .OBJDIR for the current directory. The current
directory may be read only. MAKEOBJDIRPREFIX can only
be provided in the environment.
"make" variables
Several variables control the behavior of NetBSD builds. Unless other-
wise specified, these variables may be set in either the process environ-
ment or the make(1) configuration file specified by MAKECONF.
BUILDID Identifier for the build. The identifier will be appended to
object directory names, and can be consulted in the make(1)
configuration file in order to set additional build parame-
ters, such as compiler flags.
DESTDIR Directory to contain the built NetBSD system. If set, spe-
cial options are passed to the compilation tools to prevent
their default use of the host system's /usr/include,
/usr/lib, and so forth. This pathname should not end with a
slash (/) character (for installation into the system's root
directory, set DESTDIR to an empty string). The directory
must reside on a file system which supports long file names
and hard links.
Default: Empty string if USETOOLS is ``yes''; unset other-
wise.
MAKECONF The name of the make(1) configuration file. Only settable in
the process environment.
Default: ``/etc/mk.conf''
MKCATPAGES Can be set to ``yes'' or ``no''. Indicates whether prefor-
matted plaintext manual pages will be created during a build.
Default: ``yes''
MKCRYPTO Can be set to ``yes'' or ``no''. Indicates whether crypto-
graphic code will be included in a build; provided for the
benefit of countries that do not allow strong cryptography.
Will not affect use of the standard low-security password en-
cryption system, crypt(3).
Default: ``yes''
MKDOC Can be set to ``yes'' or ``no''. Indicates whether system
documentation destined for /usr/share/doc will be installed
during a build.
Default: ``yes''
MKHOSTOBJ Can be set to ``yes'' or ``no''. If set to ``yes'', then for
programs intended to be run on the compile host, the name,
release, and architecture of the host operating system will
be suffixed to the name of the object directory created by
``make obj''. (This allows multiple host systems to compile
NetBSD for a single target.) If set to ``no'', then programs
built to be run on the compile host will use the same object
directory names as programs built to be run on the target.
Default: ``no''
MKINFO Can be set to ``yes'' or ``no''. Indicates whether GNU Info
files, used for the documentation for most of the compilation
tools, will be created and installed during a build.
Default: ``yes''
MKLINT Can be set to ``yes'' or ``no''. Indicates whether lint(1)
will be run against portions of the NetBSD source code during
the build, and whether lint libraries will be installed into
/usr/libdata/lint.
Default: ``yes''
MKMAN Can be set to ``yes'' or ``no''. Indicates whether manual
pages will be installed during a build.
Default: ``yes''
MKNLS Can be set to ``yes'' or ``no''. Indicates whether Native
Language System locale zone files will be compiled and in-
stalled during a build.
Default: ``yes''
MKOBJ Can be set to ``yes'' or ``no''. Indicates whether object
directories will be created when running ``make obj''. If
set to ``no'', then all built files will be located inside
the regular source tree.
Default: ``yes''
MKPIC Can be set to ``yes'' or ``no''. Indicates whether shared
objects and libraries will be created and installed during a
build. If set to ``no'', the entire built system will be
statically linked.
Default: Platform dependent. As of this writing, all plat-
forms except sh3 default to ``yes''.
MKPICINSTALL
Can be set to ``yes'' or ``no''. Indicates whether the ar(1)
format libraries (lib*_pic.a), used to generate shared li-
braries, are installed during a build.
Default: ``yes''
MKPROFILE Can be set to ``yes'' or ``no''. Indicates whether profiled
libraries (lib*_p.a) will be built and installed during a
build.
Default: ``yes''; however, some platforms turn off MKPROFILE
by default at times due to toolchain problems with profiled
code.
MKSHARE Can be set to ``yes'' or ``no''. Indicates whether files
destined to reside in /usr/share will be built and installed
during a build. If set to ``no'', then all of MKCATPAGES,
MKDOC, MKINFO, MKMAN, and MKNLS will be set to ``no'' uncon-
ditionally.
Default: ``yes''
TOOLDIR Directory to hold the host tools, once built. This directory
should be unique to a given host system and NetBSD source
tree. (However, multiple targets may share the same TOOLDIR;
the target-dependent files have unique names.) If unset, a
default based on the uname(1) information of the host plat-
form will be created in the .OBJDIR of src/tools.
Default: Unset.
UNPRIVED If set, then an unprivileged install will occur. The user,
group, permissions, and file flags, will not be set on the
installed item; instead the information will be appended to a
file called METALOG in the .OBJDIR of src. The contents of
METALOG is used during the generation of the distribution tar
files to ensure that the appropriate file ownership is
stored.
Default: Unset.
UPDATE If set, then all install operations intended to write to
DESTDIR will compare file timestamps before installing, and
skip the install phase if the destination files are up-to-
date. This also has implications on full builds (see next
subsection).
Default: Unset.
USETOOLS Indicates whether the tools specified by TOOLDIR should be
used as part of a build in progress. Must be set to ``yes''
if cross-compiling.
yes Use the tools from TOOLDIR.
no Do not use the tools from TOOLDIR, but refuse to build
native compilation tool components that are version-
specific for that tool.
never Do not use the tools from TOOLDIR, even when building
native tool components. This is similar to the tradi-
tional NetBSD build method, but does not verify that
the compilation tools in use are up-to-date enough in
order to build the tree successfully. This may cause
build or runtime problems when building the whole
NetBSD source tree.
Default: ``yes'' if building all or part of a whole NetBSD
source tree (detected automatically); ``no'' otherwise (to
preserve traditional semantics of the make(1) in-
clude files).
"make" variables for full builds
These variables only affect the top level ``Makefile'' and do not affect
manually building subtrees of the NetBSD source code.
MKOBJDIRS Can be set to ``yes'' or ``no''. Indicates whether object
directories will be created automatically (via a ``make
obj'' pass) at the start of a build.
Default: ``yes''
NBUILDJOBS If set, specifies the number of parallel make(1) processes
that should be run simultaneously. This can speed up
builds on SMP machines, or machines with much more CPU
power than I/O availability. This should be used instead
of the make(1) option -j, in order to ensure proper order-
ing of build components.
Default: Unset.
NOCLEANDIR If set, avoids the ``make cleandir'' phase of a full
build. This has the effect of allowing only changed files
in a source tree to be recompiled. This can speed up
builds when updating only a few files in the tree.
Default: Unset.
NODISTRIBDIRS If set, avoids the ``make distrib-dirs'' phase of a full
build. This skips running mtree(8) on DESTDIR, useful on
systems where building as an unprivileged user, or where
it is known that the system-wide mtree files have not
changed.
Default: Unset.
NOINCLUDES If set, avoids the ``make includes'' phase of a full
build. This has the effect of preventing make(1) from
thinking that some programs are out-of-date simply because
the system include files have changed. However, this op-
tion should not be used when updating the entire NetBSD
source tree arbitrarily; it is suggested to use UPDATE in
that case.
Default: Unset.
RELEASEDIR If set, specifies the directory to which a release(7) lay-
out will be written at the end of a ``make release''.
Default: Unset.
UPDATE If set, then in addition to the effects described for UP-
DATE above, this implies the effects of NOCLEANDIR.
BUILDING
"make" command line options
This is only a summary of options available to make(1); only the options
used most frequently with NetBSD builds are listed here.
-m dir Specify the default directory for searching for system Make-
file segments, mainly the files. When building any
full NetBSD source tree, this should be set to the
``share/mk'' directory in the source tree. (This is set auto-
matically when building from the top level.)
-n Display the commands that would have been executed, but do not
actually execute them. This will still cause recursion to
take place.
-v var Print make(1)'s idea of the value of var. Does not build any
targets.
var=value Set the variable var to value, overriding any setting speci-
fied by the process environment, the MAKECONF configuration
file, or the system Makefile segments.
"make" targets
These default targets may be built by running make(1) in any subtree of
the NetBSD source code. It is recommended that none of these be used
from the top level Makefile; as a specific exception, ``make obj'' and
``make cleandir'' are useful in that context.
all Build programs, libraries, and preformatted documentation.
clean Remove program and library object code files.
cleandir Same as clean, but also remove preformatted documentation, de-
pendency files generated by ``make depend'', and any other
files known to be created at build time. ``make distclean''
may be used as a synonym, for familiarity with a similar well-
known convention.
depend Create dependency files (.depend) containing more detailed in-
formation about the dependencies of source code on header
files. Allows programs to be recompiled automatically when a
dependency changes.
dependall Does a ``make depend'' immediately followed by a ``make all''.
This combined target recurses as an atomic unit, so that the
``make depend'' phase can participate in make -j parallelism.
includes Build and install system header files. Typically needed be-
fore any system libraries or programs can be built.
install Install programs, libraries, and documentation into DESTDIR.
lint Run lint(1) against the C source code, where appropriate, and
generate system-installed lint libraries.
obj Create object directories to be used for built files, instead
of building directly in the source tree.
tags Create ctags(1) searchable function lists usable by the ex(1)
and vi(1) text editors.
"make" targets for the top level
Additional make(1) targets are usable specifically from the top source
level to facilitate building the entire NetBSD source tree.
build Build the entire NetBSD system. This orders portions of the
source tree such that prerequisites will be built in the prop-
er order.
release Do a ``make build'', then package the system into a standard
release layout as described by release(7). This requires that
RELEASEDIR be set (see above).
regression-tests
Can only be run after building the regression tests in the di-
rectory ``regress''. Runs the compiled regression tests on
the local host.
The "build.sh" script
This script file is a Bourne shell script designed to build the entire
NetBSD system on any host with a Bourne shell in /bin/sh, including many
that are not POSIX compliant. Note that if a host system's /bin/sh is
unusually old and broken, the Korn Shell (/bin/ksh), if available, may be
a usable alternative.
All cross-compile builds, and most native builds, of the entire system
should make use of build.sh rather than just running ``make''. This way,
the make(1) program will be bootstrapped properly, in case the host sys-
tem has an older or incompatible ``make'' program.
When compiling the entire system via build.sh, many make(1) variables are
set for you in order to help encapsulate the build process. In the list
of options below, variables that are automatically set by build.sh are
noted where applicable.
The following are available command line options that may be supplied to
build.sh:
-a arch Set the value of MACHINE_ARCH to arch.
-B buildid
Set the value of BUILDID to buildid. This will also append the
build idenfitier to the name of the ``make'' wrapper script so
that the resulting name is of the form ``nbmake-MACHINE-
BUILDID''.
-b Bootstrap ``make'' and create a nbmake-MACHINE script (see be-
low).
-d Build a full distribution. This differs from a normal build in
that etc files will also be installed. Note this does not
build a ``release''; no release sets are placed in ${RE-
LEASEDIR}.
-j njob Set the value of NBUILDJOBS to njob. This provides similar
functionality to the familiar ``make -j'', but preserves the
ordering of the top level ``make build''.
-m mach Set the value of MACHINE to mach. This will also override any
value of MACHINE_ARCH in the process environment with a value
deduced from mach, unless -a is specified. All cross builds
require -m, but if unset on a NetBSD host, the host's value of
MACHINE will be detected and used automatically.
-n Show the commands that would be executed by build.sh, but do
not make any changes. This is similar in concept to ``make
-n''.
-o Set the value of MKOBJDIRS to ``no''.
-r Remove the contents of DESTDIR and TOOLDIR before building
(provides a clean starting point). This will skip deleting
DESTDIR if building on a native system to the root directory.
-t Build and install the host tools from src/tools only. This op-
tion implies -b.
-u Set the UPDATE variable.
-w wrapper
Create the nbmake wrapper script (see below) in a custom loca-
tion, specified by wrapper. This allows, for instance, to
place the wrapper in PATH automatically. Note that wrapper is
the full name of the file, not just a directory name.
-D dest Set the value of DESTDIR to dest.
-O obj Create an appropriate transform macro for MAKEOBJDIR that will
place the built object files under obj. For instance, a set-
ting of /usr/obj will place build-time files files under
/usr/obj/bin, /usr/obj/lib, and so forth.
-R rel Set the value of RELEASEDIR to rel. Setting this option will
cause build.sh to run ``make release'' instead of ``make
build''.
-T tools Set the value of TOOLDIR to tools. If set, the bootstrap
``make'' will only be rebuilt as needed (when the source files
for make(1) change).
-U Set the UNPRIVED variable.
The "nbmake-MACHINE" wrapper script
If using the build.sh script to build NetBSD, a nbmake-MACHINE script
will be created in TOOLDIR/bin upon the first build to assist in building
subtrees on a cross-compile host.
nbmake-MACHINE can be invoked in lieu of make(1), and will instead call
the up-to-date version of ``nbmake'' installed into TOOLDIR/bin with sev-
eral key variables pre-set, including MACHINE, MACHINE_ARCH, and TOOLDIR.
This script can be symlinked into a directory listed in PATH, or called
with an absolute path.
SEE ALSO
make(1), hier(7), release(7)
HISTORY
The USE_NEW_TOOLCHAIN based build scheme was introduced in the ``NetBSD-
current'' development sources between NetBSD 1.5 and NetBSD 1.6.
BUGS
Many platforms are not yet using the USE_NEW_TOOLCHAIN system.
NetBSD March 5, 2002 8